Showing papers on "Procedural texture published in 2016"
11 Jul 2016
TL;DR: This paper proposes to study procedural, aperiodic microstructures inspired by Voronoi open-cell foams, and applies the approach to the fabrication of objects with spatially varying elasticity, including the implicit modeling of a frame following the object surface and seamlessly connecting to the micro Structures.
Abstract: Microstructures at the scale of tens of microns change the physical properties of objects, making them lighter or more flexible. While traditionally difficult to produce, additive manufacturing now lets us physically realize such microstructures at low cost. In this paper we propose to study procedural, aperiodic microstructures inspired by Voronoi open-cell foams. The absence of regularity affords for a simple approach to grade the foam geometry --- and thus its mechanical properties --- within a target object and its surface. Rather than requiring a global optimization process, the microstructures are directly generated to exhibit a specified elastic behavior. The implicit evaluation is akin to procedural textures in computer graphics, and locally adapts to follow the elasticity field. This allows very detailed structures to be generated in large objects without having to explicitly produce a full representation --- mesh or voxels --- of the complete object: the structures are added on the fly, just before each object slice is manufactured. We study the elastic behavior of the microstructures and provide a complete description of the procedure generating them. We explain how to determine the geometric parameters of the microstructures from a target elasticity, and evaluate the result on printed samples. Finally, we apply our approach to the fabrication of objects with spatially varying elasticity, including the implicit modeling of a frame following the object surface and seamlessly connecting to the microstructures.
213 citations
1 Jan 2016
TL;DR: A noise model based on non-uniform random distributions of multiple Gaussian functions for synthesizing semi-structured textures is presented, extending the LRP noise model by using a spot noise based on a controlled distribution of kernels (spots), as an alternative formulation to local noises aligned on a regular grid.
Abstract: Procedural noises based on power spectrum definition and random phases have been widely used for procedural texturing, but using a noise process with random phases limits the types of possible patterns to Gaussian patterns (i.e. irregular textures with no structural features). Local Random Phase (LRP) Noise has introduced control over structural features in a noise model by fixing the frequencies and phase information of desired features, but this approach requires storing these frequencies. Space distortion and randomization must also be used to avoid repetitions and periodicity. In this paper, we present a noise model based on non-uniform random distributions of multiple Gaussian functions for synthesizing semi-structured textures. We extend the LRP noise model by using a spot noise based on a controlled distribution of kernels (spots), as an alternative formulation to local noises aligned on a regular grid. Spots are created as a combination of Gaussian functions to match either a specific power spectrum or a user-defined texture element. Our noise model improves the control over local structural features while keeping the benefits of LRP noise.
13 citations
17 May 2016
TL;DR: It is shown that fixing oscillation of contrast opens many doors to a more controllable authoring of stochastic texturing, and some of the new reachable possibilities such as constrained noise content and bridges towards very different families of look such as cellular patterns, points-like distributions or reaction-diffusion are explored.
Abstract: We identify and analyze a major issue pertaining to all power-spectrum based texture synthesis algorithms – from Fourier synthesis to procedural noise algorithms like Perlin or Gabor noise – , namely, the oscillation of contrast (see Figures 1,2,3,7). One of our key contributions is to introduce a simple yet powerful descriptor of signals, the Spectrum of Variance (not to be confused with the PSD), which, to our surprise, has never been leveraged before. In this new framework, several issues get easy to understand measure and control, with new handles, as we illustrate. We finally show that fixing oscillation of contrast opens many doors to a more controllable authoring of stochastic texturing. We explore some of the new reachable possibilities such as constrained noise content and bridges towards very different families of look such as cellular patterns, points-like distributions or reaction-diffusion.
7 citations
15 Sep 2016
TL;DR: An extension of the Locally Controlled Spot Noise and a visualization pipeline for volumetric fuzzy details synthesis and a new method based on order independent splatting to compute a fast view dependent approximation of shell noise at interactive rates are presented.
Abstract: In this paper, we present an extension of the Locally Controlled Spot Noise and a visualization pipeline for volumetric fuzzy details synthesis. We extend the noise model to author volumetric fuzzy details using filtered 3D quadratic kernel functions convolved with a projective non-uniform 2D distribution of impulses. We propose a new method based on order independent splatting to compute a fast view dependent approximation of shell noise at interactive rates. Our method outperforms ray marching techniques and avoids aliasing artifacts, thus improving interactive content authoring feedback. Moreover, generated surface details share the same properties as procedural noise: they extend on potentially infinite surfaces, are defined in an extremely compact way, are non-repetitive, continuous (no discrete voxel-artifacts when zooming) and independent of the definition of the underlying surface (no surface parameterization is required).
4 citations
1 May 2016
TL;DR: A novel technique for procedural texturing and scattering of terrain cover based on cascading input parameters is presented, which can create plausible, visually appealing landscapes.
Abstract: This paper describes an overall process of procedural generation of natural environments through terrain generation, texturing and scattering of terrain cover. Although described process can be used to create various types of environments, focus of this paper has been put on Mediterranean which is somewhat specific and has not yet received any attention in scientific papers. We present a novel technique for procedural texturing and scattering of terrain cover based on cascading input parameters. Input parameters can be used to scatter vegetation simply by slope and height of the terrain, but they can also be easily extended and combined to use more advanced parameters such as wind maps, moisture maps, per plant distribution maps etc. Additionally, we present a method for using a satellite image as an input parameter. Comparing results with real-life images shows that our approach can create plausible, visually appealing landscapes.
3 citations
27 Jan 2016
TL;DR: A texture decomposition method, called difference map, is described for the analysis of given example generated by multi-resolution Perlin noise, which illustrates the relationship between difference map with corresponding Perlin band noise and explains how the appropriate parameters can be estimated.
Abstract: Procedural noise has many advantages such as memory compactness, non-periodicity, etc. However, it is hard to obtain appropriate textures through direct controlling of parameters. Procedural noise by example has been presented as a solution. In this paper, we describe a texture decomposition method, called difference map, for the analysis of given example generated by multi-resolution Perlin noise. We illustrate the relationship between difference map with corresponding Perlin band noise and explain how the appropriate parameters can be estimated. Finally, we validate our method through the experimental results and show the compatibility to real-time interactive systems.
1 citations
TL;DR: This paper describes four examples of stylistic description, defined by a handwritten fitness function that rates how well a given texture meets this style, that are used in a prototype tool intended to assist a designer or artist by automatically discovering collections of candidate textures.
Abstract: Evolutionary texture synthesis is used in a prototype tool intended to assist a designer or artist by automatically discovering collections of candidate textures to fit a given stylistic description. The textures used here are small colour images created by procedural texture synthesis. This paper describes four examples of stylistic description. Each is defined by a handwritten fitness function that rates how well a given texture meets this style. Genetic programming uses the fitness function to evolve programs written in a texture synthesis language. This system automatically generates a catalogue of variations on the given theme. A designer could then visually scan through these textures to pick out ones that seem aesthetically interesting. Their procedural 'genetic' representation would allow textures to be further adjusted by interactive evolution. The procedural representation also allows re-rendering textures at arbitrary pixel resolutions and provides a way to store them in a highly compressed form allowing lossless reconstruction.
1 citations
TL;DR: This paper describes the development and use of PhotoFrac, an application that allows artists and designers to turn digital images into fractal patterns interactively and presents results and qualitative analyses of the tool by four artists who used the photoFrac application to create new artworks from original digital images.
Abstract: In this paper, we describe the development and use of PhotoFrac, an application that allows artists and designers to turn digital images into fractal patterns interactively. Fractal equations are a rich source of procedural texture and detail, but controlling the patterns and incorporating traditional media has been difficult. Additionally, the iterative nature of fractal calculations makes implementation of interactive techniques on mobile devices and web apps challenging. We overcome these problems by using an image coordinate based orbit trapping technique that permits a user-selected image to be embedded into the fractal. Performance challenges are addressed by exploiting the processing power of graphic processing unit (GPU) and precomputing some intermediate results for use on mobile devices. This paper presents results and qualitative analyses of the tool by four artists (the authors) who used the PhotoFrac application to create new artworks from original digital images. The final results demonstrate a fusion of traditional media with algorithmic art.
1 citations
24 Oct 2016
TL;DR: This paper proposes to compute non-uniform density cellular noise by using a procedural quad-tree and explains how to efficiently traverse the tree recursively (CPU) and iteratively (CPU and GPU).
Abstract: Procedural cellular textures have been widely used in movie production to reproduce various natural and organic looks. The advantage of procedural texture is to trade memory for computer power and obtain potentially unlimited resolution. In this paper, we propose to compute non-uniform density cellular noise by using a procedural quad-tree. We will explain how to efficiently traverse the tree recursively (CPU) and iteratively (CPU and GPU).
27 Feb 2016
TL;DR: A stable shading method and a procedural shading model that enables real-time rendering of sub-pixel glints and anisotropic microdetails resulting from irregular microscopic surface structure to simulate a rich spectrum of appearances ranging from sparkling to brushed materials are presented.
Abstract: We present a stable shading method and a procedural shading model that enables real-time rendering of sub-pixel glints and anisotropic microdetails resulting from irregular microscopic surface structure to simulate a rich spectrum of appearances ranging from sparkling to brushed materials. We introduce a biscale Normal Distribution Function (NDF) for microdetails to provide a convenient artistic control over both the global appearance as well as over the appearance of the individual microdetail shapes, while efficiently generating procedural details. Our stable rendering approach simulates a hierarchy of scales and accurately estimates pixel footprint at multiple levels of detail to achieve good temporal stability and antialiasing, making it feasible for real-time rendering applications.
1 Nov 2016
TL;DR: A novel Convolutional Neural Network based texture model consisting of two summary statistics (the Gramian and Translation Gramian matrices) as well as spectral constraints is presented, and it is found that the Fourier Transform improved the quality of the generated textures.
Abstract: Procedural texture generation enables the creation of more rich and detailed virtual environments without the help of an artist. However, finding a flexible generative model of real world textures remains an open problem. We present a novel Convolutional Neural Network based texture model consisting of two summary statistics (the Gramian and Translation Gramian matrices), as well as spectral constraints. We investigate the Fourier Transform or Window Fourier Transform in applying spectral constraints, and find that the Window Fourier Transform improved the quality of the generated textures. We demonstrate the efficacy of our system by comparing generated output with that of related state of the art systems.